Over the last few decades, biodegradable polymers have been applied to a number of applications in drug delivery and regenerative medicine. While naturally derived biodegradable polymers have distinct bioactivity and cell binding properties, they are difficult to isolate, derivatize and purify. Synthetic polymers also have the potential for immunogenic responses. Synthetic biodegradable polymers have a number of advantages over natural materials, especially the chemical diversity of monomers that can be utilized to tailor the chemical, mechanical and degradation properties of the polymer. There are a number of biodegradable polymers including poly(ε-caprolactone) (PCL), poly(lactic acid) (PLA), poly(glycolide) (PGA), and copolymers thereof that are used clinically and while their properties in vitro and in vivo are largely understood, their range of physical and chemical properties is somewhat limited. Efforts have been made to diversify the pool of synthetic polymers to meet design criteria for more advanced applications.
Currently available vascular grafts fail at small diameters (for example diameters below 5 mm) as a result of acute thrombotic occlusions or chronic anastomic hyperplasia. The failure of small diameter vascular grafts may be traced to the lack of functional intimacy, surface property mismatch, compliance mismatch and microstructure mis-match as a result of the use of polyesters such as polyethylene terephthalate or expanded polytetrafluoroethylene.
Presently there is a need to produce vascular grafts from polymers that have some or all of the following properties biodegradability, resorbable non-toxic hydrolysis byproducts, tunable mechanic properties, synthetic flexibility, and the ability to add functional groups.